Java Interview Question #1 : Is Final Method more efficient in Java ?

Que 1. Final Vs Non Final Method, Which is more efficient ?

Answer : Final

1. Final methods execute more efficiently than non final method.
2. Compiler knows at compile time that a call to a final method won’t be overridden by some other method

Let’s See, How ?

Consider the final method,

package com.c4learn.inheritance;
public class ShapeClass {
    final void setShape() {
    	System.out.println("I am Inherited");;   	
    }
    public static void main(String[] args) {
    	Circle c1 = new  Circle();
    	c1.setShape();
    }
}
class Circle extends ShapeClass {
}

Whenever we create an object of the child class then compiler will check whether method written inside the parent class is overriden or not at run time.

final void setShape() {
    System.out.println("I am Inherited");;   	
}

In this case compiler already knows that, method is declared as final so it does not waste time in checking whether method is final or not.